This invention relates to compositions and methods for treating a reflective-transmissive surface to reduce reflected glare and to surfaces that have been so treated.
Items of various sorts are viewed through an abutting transmissive surface. For example, glass or plastic surfaces are used to protect the electronic viewing screens. By the term "electronic viewing screens," I mean to include viewing screens of all types including, without limitation, screens for television sets, video display terminals, television monitors, test equipment screens, word processor screens, mini-computer screens, main frame computer monitors, other cathode-ray tube screens, liquid crystal displays (LCD's), light emitting diodes (LED's), watches, oscilloscopes, plasma screens, and electroluminescent displays (EL's). By television sets and television monitors, I mean to include black and white television, color television, red/green/blue monitors, green monitors, and amber monitors; I also mean to include digital as well as raster scanning television sets and vector sets. Artwork or photographs may have intrinsically reflective surfaces, or they may be protected by glass or plastic.
Locations for viewing such surfaces may generate serious glare. For example, the surfaces may reflect room lights or light entering through room windows. In the workplace, various equipment may reflect fluorescent lights or incandescent lights as well as window light. Such glare is annoying. More important, it prevents transmission of information and images, it causes squinting and headaches, and it is generally fatiguing and efficiency reducing. There have been considerable complaints about these problems from those who use such screens regularly--for example, office workers.
The problem to be addressed is allowing light to pass from the viewing surface to the viewer, while at the same time significantly reducing or eliminating reflections from that surface. Specifically, where the viewing surface is a glass or plastic surface, light must be transmitted through the surface from an object immediately therebehind, and light impinging on the surface from the viewer's side must be effectively dispersed to avoid objectionable reflection.
In some cases, glare reduction may be achieved at the expense of the quality of the transmitted image. It is highly desirable to be able to control the amount of glare reduction so that glare reduction and transmitted image quality are maximized for a given application.
Various efforts to reduce glare have been disclosed.
Junge et al. U.S. Pat. No. 3,374,130 discloses an etching process for producing low specular reflecting or low image reflecting surfaces on glass.
Leinen U.S. Pat. No. 4,168,332 discloses a non-glare abrasion resistant coating for glass or plastic that protects and overlies artwork. The coating is made by spraying a polymerizable solution comprising an epoxy prepolymer of an epoxy-terminated silane and an oxirane copolymer onto the glass.
King U.S. Pat. No. 3,697,277 discloses a non-glare reflective photographic print having a matte-surfaced polyester film--for example, poly (ethylene)terephthalate, permanently bonded to the photographic emulsion.
Marks et al. U.S. Pat. No. 3,679,451 discloses coatings for decreasing reflected images from the surface of a transparent sheet used for displays; the coatings are mixtures of organic and inorganic polymers--for example, a mixture of polyvinyl butyral, polyvinyl alcohol acetate copolymer and polysilic acid.
Bohum, U.S. Pat. No. 3,736,050, discloses a filter with an anti-reflective coating to be used with a cathode-ray tube.
Hyman et al., U.S. Pat. No. 3,576,356, disclose a multi-layer anti-glare coating for a cathode-ray tube implosion shield. The coating is a semiconductive material sandwiched by dielectric layers so that a voltage pen can make electrical contact through the dielectric layers to the semiconductive layer.
Barnes, U.S. Pat. No. 2,734,142, discloses a reflection reduction coating comprising discrete microgranular transparent solid particles that are deposited by a spinning process on a lens adapted for a cathode-ray tube. A color neutralizing layer is provided at the surface of the lens.